USS Washer, Flat Washer Type USS, Dimensional Standards ASME B18.22.1, Material Steel, Material Grade/Class Through Hardened, Finish Armor Coat(TM), For Screw Size 1/4 in, Inside Diameter 0.313 in, Outside Diameter 3/4 in, Maximum Thickness 5/64 in, System of Measurement Inch, Minimum Thickness 5/64 in, Material Quality Standards ASME B18.22.1, Pack Size Small Pack, Resistance Properties Corrosion-Resistant, Rust-Resistant, Rockwell Hardness C38, Tensile Strength 150,000 psi